Angle tooth cutter



Feb. 7, 1933. s. EVANS ET AL ANGLE TOOTH CUTTER Filed March 3, 1930 INVENTORS BY Ii. W

ATTORNEY Patented Feb. 7, 1933 UNITED STATES PATENT OFFICE sa'rrr Evans AND JOHN a. rraname'ron, or nous'ron, 'rnxas, assrenons 'ro avenue 'rooL serum, or nous'ron, rams, a GOBPORATION or Texas ANGLE TOOTH CUTTER Application ma larch a.

This invention relates to cutters for use on roller earth borin drills, particularly cone shaped cutters suc as are employed on the drills.

Such drills have a head, on the forward end of which are supported a plurality of cut,- tersusually twoof approximately conical shape, mounted and formed to roll with an approximately true roll-in motion upon the bottom of the well hole. hese cutters when thus positioned, present the base or largest circumference, of the cutter adjacent the outer wall of the hole. The most diflicult portion of the hole to cut lies immediately ad'acent the side wall upon the bottom. be cutting teeth upon the cutters penetrate the formation with a sort of chisel stroke, and the material displaced by the cuttin teeth must be moved u wardly and laterally at; the penetration of eformation by thetee Where there is room for the dis laced material to do so, this material will moved into the spaces between the cutter teeth and will be can htby the stream of flushin fluid andcarrie awa to the surface. ut where the outer teet adjacent the side wall of the hole netrate the formation the material cannot b: displaced outwardly because of the wall? of the hole, but can only be moved inwardly. As a result the material is not removed and carried away so efiectively around the outer margin of the well bottom, and a layer of parloosened detritus accumulates at this portion of the hole and retards progress. Although the teeth on the cutter are larger along the outer rims of the cutters, the teeth travel in a larger circle and hence cover more area,

' and the cutting is more diflicult because the material displaced by the teeth at that point is not all moved inwardly and brought into the influence of the flushing fluid.

It is an object of the invention to provide a cutter with teeth formed thereon so as to remove the cuttin effectively from the outer portion of the w bottom.

It is desired to cut all portions of the well bottom uniformly, so that the most effective brin 1930. Serial No. 488,588.

cutting action of the cutters may be obtained. I

It is an object to so form and incline'the teeth adjacent the outer portion of the drill that the cuttings will be forced away from the wall of the hole and into a position where they may be reached and carried away by the flushing fluid.

In the drawing Fig. 1 is a side elevation of the lower end of a drill bit equipped with cutters formed to illustrate the invention.

Fi 2 is a plan view of the bottom of a hole and i ustratmg the tracks of the cutter teeth thereon. r Y

Fig. 3 is a broken elevation of the base of one-of the conical cutters.

The type of drill here illustrated is in common use. The head 1 of the drill has a V- shaped slot 2 at the lower end on the walls of which are mounted two opposite conical shaped cutters 3.

. Positionin the 'conical cutters in this way the si es of the cones on the lower side para el with the bottom of the hole so as to cut an approximatel flat bottomed hole.

The invention resldes in the she. e and position of the cutting teeth u on t e cutters. Heretofore the teeth have em formed in .rows lon 'tudinally of the elements of the cones an with the crests presented radially along the cone in lines running from base to apex thereof. The teeth are also in rows circumferentially of the cutting area. 7

In the present'cutters the teeth 4 on the inner rows are still formed with the crests running longitudinally of the cutter. In the two outer rows 5 and. 6 the teeth are cut on the cone with the crests set at an angle inclined inwardly and rearwardly from the outer circumference of the hole. This will be best understood b reference to the cutter tracks in Fig. 2. are shown at 4', 5' and 6' respectively. The drill head is rotated in a clockwise direction, and it will be seen that the teeth are formed to engage the formation around the outer portion of the hole and move the formation inwardly toward the center with a plow like action. The outer teeth 6 penetrate the formation at such an angle that the material displaced is crowded away from the wall of e imprints of the teeth the hole and into the groove 7 where the flush ing fluid will catch it and carry it away. The action of the next inner row will also tend to move the material inwardl and as a re 5 sult of the action of-the teet 5 and 6, the

enetrating action of the outer teeth is eaty improved, and the progress of the it is not held u by accumulations around the outer margln adjacent the wall. 10 It will be noted that the two cutters are mates. The rows of teeth of one cone are opposed to the grooves between the rows of teeth upon the matin cone. Thus each cutter cuts its own trac upon the bottom of the hole. The view of the bottom shown in Fig. 2, therefore, shows the track of but one cutter. The track of the other cutter would be similar, but would lie in the uncut portions 8 between the tracks of the first cutter. It is also important that all the cutters have the teeth thereon similarly inclined to push the material inwardly.

The advantages of this type of cutter have already been noted. The cutters will cut faster and wear better, because the drill is not held up by the material adj acentthewellwall. This portion ofthe hole will be cut efiectively, and the material will be moved inwardly where it can be carried away by the flushing What is claimed as new is:

1. A cutter for well drills, said cutter be-. ing of approximately conical shape, teeth. formed inendless circumferential rows on said cutter, the rows adjacent the apex thereof being extended radially away from said apex, the teeth adjacent the base thereof being inclined relative to the radius of each cutter to move the material toward the said apex as said drill is rotated.

' 2. A cutter for well drills, said cutter being of approximately conical shape, teeth formed in endless circumferential rows on said cutter, the rows adjacent the apex thereof bein extended radially away from said apex, t e crests of said teeth adjacent the base thereof being inclined inwardly and rearwardly from the forward advancing ends of said teeth, so as to move the material cut thereby inwardly.

3. In a well drill, a head, two opposed coni- 'cal shaped cutters mounted on the forward end thereof, and separate rows of teeth on both said cutters, each tooth on the outer row having a cutting edge inclined inwardly and rearwardly from the direction of rotation to move the material on the well bottom away from the wall of the hole.

in testimony whereof, we hereunto aifix 0 our signatures, this 28th day of February,

SETH EVANS.

JOHN A. HERRINGTON. 

